1. Field of the Invention
This invention relates to a vapor-phase method for the synthesis of diamond films or granules possessing abrasive wear resistance, corrosionproofness, high thermal conductivity, and high specific Young's modulus and finding utility in abrasive materials, grinding materials, optical materials, super hard material tools, sliding materials, corrosionproofing materials, acoustic vibration materials, blade edge components, etc.
2. Prior Art Statement
Up to now synthesis of diamond has been carried out either by synthesis under extremely high pressure in the presence of a catalyst of iron or nickel or by direct conversion of graphite by the impact of explosion.
In the art of low-pressure CVD, recent years have seen progress in the development of a method for synthesizing diamond by imparting an excited state to a gaseous mixture of hydrogen with a hydrocarbon or an organic compound containing nitrogen, oxygen, etc. by means of a hot filament, a microwave plasma, a high-frequency plasma, a direct-current discharge plasma, or a direct-current arc discharge.
The conventional CVD method mentioned above has required a special apparatus for exciting the raw material gas to an extent sufficient for synthesis of diamond. No matter which of the aforementioned sources of excitation may be employed, it is difficult to obtain large-area diamond deposition.